Due to the economic development and industrialization, the population is increased rapidly so that resources on land are not enough for use. All developed countries are seeking and developing new resources actively. In this regard, the sea is surely the best option because it occupies the largest surface area of the Earth (up to 70%), has the depth of up to eleven thousand meters and possesses almost 90% of resources on the Earth. The sea not only has abundant and various biological resources, but also are rich in a large number of minerals and oil. In recent years, owing to the advancement of micro sensors and the development of communication technologies, the exploitation and exploration of resources are not limited to the distance and space.
Currently, there are two kinds of underwater wireless sensors. The first underwater wireless sensor is implemented by disposing a buoy on the sea surface, and putting down the sensor to the required depth via a cable connected to the buoy. The second underwater wireless sensor is implemented by disposing an anchor at the bottom of the sensor, and pulling the floating sensor with an anchor cable fixed on the seabed. Although the first underwater wireless sensor can control the depth that the sensor submerges to, it is limited to the length and strength of the cable connected to the buoy; besides, it will block the ships on the sea surface from sailing. The second underwater wireless sensor will not block the ships on the sea surface form sailing, but the depth that the sensor submerges to cannot be controlled due to the complicated topography of the sea bed; besides, the sensor will sink at the sea bed forever after it runs out of power, which causes pollution.
In order to overcome the drawbacks in the prior art, an underwater wireless sensor is provided. The particular design in the present invention not only solves the problems described above, but also is easy to be implemented. Thus, the present invention has the utility for the industry.